1. Field of the Invention
The present invention relates generally to Anthropomorphic Test Devices (ATD) and, more particularly, to an adjustable spine joint assembly for an ATD that can be used to assess and predict injuries under crash, under body explosive, and aerospace ejection seat testing environments.
2. Description of the Related Art
Automotive, aviation, and other vehicle manufacturers conduct a wide variety of collision testing to measure the effects of a collision on a vehicle and its occupants. Through collision testing, a vehicle manufacturer gains valuable information that can be used to improve the vehicle, authorities examine vehicles to submit type approval, and consumer organizations provide information on vehicle safety ratings to the public.
Impact testing often involves the use of anthropomorphic test devices (ATDs), better known as “crash test dummies.” During the testing, an operator places a crash test dummy inside a vehicle, and the vehicle undergoes a simulated collision, UBB, or ejection. The testing exposes the crash test dummy to high inertial loading, and sensors inside the crash test dummy, such as load cells, displacement sensors, accelerometers, pressure gauges, angle rate sensors, and the like, generate electrical signals of data corresponding to the loading. Cables or wires transmit these electrical signals of data to a data acquisition system (DAS) for subsequent processing. This data reveals information about the effects of the impact on the crash test dummy and can be correlated to the effects a similar impact would have on a human occupant.
In order to obtain more accurate test data, test engineers attempt to maximize what is known as the “biofidelity” of the crash test dummy. Biofidelity is a measure of how well the crash test dummy reacts like a human being in a vehicle impact test environment. A crash test dummy reacting as an actual human during a collision is said to have a high biofidelity. Accordingly, a crash test dummy having a high biofidelity will provide more accurate information from a collision test relative to the effect of the collision on a human being. Thus, ATD design engineers design crash test dummies with the proper anthropometry that reflects a total weight, center of gravity, mass moment of inertia and range of motion similar to that of a human body so as to increase the biofidelity of the crash test dummy.
Currently, an ATD design requires a design that allows torso angle adjustment to represent different seating postures. For example, a typical vehicle driver has a seatback at approximately twenty-five (25) degrees reclined. Moreover, a truck has a seatback that is nearly upright. In contrast, a race car seat back may be in a more reclined position. These seat configurations require an ATD to have the ability to adjust the torso angle in order to be able to fit into these seat configurations. The existing ATD design uses a teeth design concept to adjust the torso angles. If a continuous adjustment with small angle increment is necessary, this design offers simplicity. However, difficulties were experienced in operation. The angle adjustment is cumbersome since the two halves of the teeth design have to be completely disengaged to allow any adjustment to happen. No support to the ATD torso is provided from the design when the two halves are apart and the ATD torso tends to fall all the way down and make the adjusting process frustrating for a technician. The existing ATD torso does not offer any position locating feature to assist the alignment. In addition, the teeth of the existing ATD torso are frequently damaged in operation. Thus, there is a need in the art for a new adjustable spine joint assembly for a crash test dummy that provides for a human range of motion.